BIO-MED DEVICES IC-2A Service Manual page 36

control to 1 second, the EXPIRATORY TIME control to 2 seconds, the FLOW
RATE control to 30 lpm, the MAX. PRESSURE control to maximum (fully
counterclockwise), and the PEEP/CPAP control to zero (fully clockwise).
Decrease the inspiratory effort by turning the INSPIRATORY EFFORT control
counterclockwise until the IC-2A Ventilator starts to trigger itself (auto-
cycling).
NOTE: Auto-cycling is not to be confused with the regular timed cycling
controlled by the inspiratory and expiratory settings. Auto-cycling can be
detected by a very short or non-existent expiratory time and also by the
activation of the DEMAND indicator at the beginning of an inspiratory
cycle without a vacuum being applied to the patient circuit.
b. Check that feedback resistor line pressure is 5 psi when auto-cycling. This
resistor is attached to a T-connector.
1. Disconnect the brown tubing (to Port 2 of gate 7) at the T-connector.
2. Connect the 60 psi test gauge to the open port of the T-connector.
3. If the test gauge does not read 5 psi when auto-cycling, adjust the
pressure by turning the resistor adjusting screw clockwise (increase
pressure) or counterclockwise (decrease pressure).
4. Disconnect the test gauge and re-connect the brown tubing to the T-
connector. Use the longer tubing if line must be bent to connect.
c. While the IC-2A Ventilator is auto-cycling, increase the inspiratory effort to the
point where it just stops auto-cycling.
patient circuit and note from the Pressure Gauge the pressure needed to
trigger the Ventilator. If it took more than 0.5 cmH
of the demand variable resistor (item 41) counterclockwise about one-eight
turn. If the Ventilator starts to auto-cycle, readjust the inspiratory effort so that
the auto-cycling just stops. Apply a slight negative pressure on the patient
circuit and note from the Pressure Gauge the pressure needed to trigger the
Ventilator. Continue to adjust the demand variable resistor until the Ventilator
triggers when a vacuum of 0.5 cmH
d. Decrease the flow rate to 20 lpm and retest the inspiratory effort. It may not
be possible to set the inspiratory effort low enough without the Ventilator auto-
cycling. By turning the demand variable resistor slightly clockwise it should
be possible to set the inspiratory effort low enough to get a trigger pressure of
0.5 cmH O or less. Recheck the demand circuit response at 30 lpm. If it is
2
not possible to attain this sensitivity, the demand valve should be replaced.
e. Place a test lung on the output of the patient circuit and rotate the
PEEP/CPAP control fully counterclockwise.
CPAP switch to MANUAL CPAP. Decrease the inspiratory effort until the
ventilator starts auto-cycling or the inspiratory effort control reaches its
maximum travel position. Squeeze the test lung and release to trigger the
Ventilator, while watching the gauge. No more than 2 cmH
Apply slight negative pressure to
O, turn the adjusting screw
2
O or less is applied to the patient circuit.
2
Switch the CYCLE/MANUAL
O lower than the
2
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